Electrode assembly



Dec. 17, 1940-- N GREEN 2,225,445

ELEc'm'GDE ASSEMBLY Filed Nov. 30, 1939 [IIIIIIIIII/IIIIIIIIII]!!!I, I, 7 I I INVENTOR. GRVAL H. GREEN BY 4%7 a ATTORNEY.

Patented Dec. 17, 1940 UNITED STATES ELECTRODE ASSEMBLY Norval H. Green, Wood-Ridge, N. J., a'ssignor to Radio Corporation of America, a, corporation of Delaware Application November 30, 1939, s rial No. 306,798

4 Claims.

My invention relates to electron discharge devices and is particularly directed to improvements in the electrode supporting means.

It is an object of my invention to support the electrode assembly very rigidly on the header or stem of the envelope enclosing the assembly.

A further object of my invention is improved supporting means for an electrode assembly that is easy to assemble, rugged in construction and inexpensive to manufacture.

The usual electrode assembly comprises two spaced parallel insulating spacers or plates for holding the ends of concentric tubular electrodes. The electrodes when assembled with their spacers must be held loosely together until the spacers are attached to support rods on the stem. The support rods are generally passed through holes in the spacers and small metal tabs or eyelets are spot welded to the rods to lock the spacers in place.

According to my invention a single U-shaped bracket with offset bends is placed astraddle the electrode assembly so that the shoulders of the bends bear against the spacers to hold the electrode assembly together without the aid of the usual spacer-to-support rod fasteners. The bracket locks the assembly together and the entire unit is rigidly supported in its envelope by the ends of the bracket.

A full understanding of my invention may be had by referring to the accompanying drawing in which Figure 1 is a perspective view of my improved electrode supporting means, Figure 2 is an elevation of my electrode support, and Figures 3 and 4 are plan views of the spacers of my novel electrode assembly.

The electrodes shown by way of example in the drawing comprise a cathode I, grid 2 and anode 3, supported at their ends in insulating spacers or plates 4 and 5. Preferably the plate is provided at each end with ears that may be threaded through openings in the spacers, and shoulders 3a on the ears may be conveniently pressed in the metal of the anode to provide an abutment for the anode against the inner surfaces'of the spacers to hold the spacers apart and in fixed spaced relation.

According to my invention the unitary electrode assembly is supported on a bracket 6 comprising a U-shaped rod or wire with a. transverse portion across the upper end of the assembly and the two legs 1 and 8 of the bracket extending downwardly through the spacers on opposite sides of the electrodes and secured at their ends to the stem of the enclosed envelope. The stem may be of the re-entrant type with studs embedded in the press of the stem to which the ends of the brackets may be attached, or the stem may be of the fiat glass disc type commonly used in metal envelopes. The fiat type stem is shown with a metal sealing ring from opposite sides of which are struck up ears for attachment to the ends of the bracket. The electrode assembly is prevented from sliding upward or downward on the bracket by'two pairs of offset bends 9, l0, II and [2 in the legs of the bracket, the preferred shape of the bracket, shown best in Figure 2, comprising outwardly extending offsets, the shoulders of bends 9 and Ill bearing against the upper surface of the upper spacer and the shoulders of bends H and I2 bearing against the under surface of the lower spacer.

The upper spacer l may conveniently be provided with two notches l3 at opposite edges of the spacer and the lower spacer provided with two elongated holes Id of such a radial length that they may receive the offset bends II and I2 of the bracket. The distance between the shoulders of the two pairs of bends is slightly greater than the distance from shoulder-to-shoulder on the anode, so that the spacers are wedged between the anode and the bracket bends.

To assemble electrodes with my novel supporting means the cathode, grid and anode electrodes are telescoped one into the other and end spacers threaded over the ends of the electrodes. The U-shaped rod is lowered over the upper spacer, sliding the legs into the notches of the upper spacer, and by slightly pressing the legs together their ends are passed through the holes M in the lower spacer. When released the natural resilience of the bracket snaps the shoulders of the lower offset bends to the outer edges of the holes and effectively locks the assembly together. The electrodes thus assembled are rigid and, without welded tabs, eyelets or other fastening means, may be handled throughout subsequent manufacturing processes without displacement or misalignment of any of the electrodes. The ends of the bracket may then be fastened, as by spot welding, to the studs or ears of the press and sealed into an envelope and exhausted in the usual Way.

Copper-plated steel or nickel-plated iron wire about .040" in diameter may be easily formed on automatic presses into the U-shaped bracket with the offset bends. This wire although easily formed is stiff and when welded at its ends to the press so rigidly supports the electrode assembly of the conventional receiver tube that electrode- 

